[#P2600] Shortest superstring of the binary Lyndon words of length eight
Problem. What is the minimum length of a binary word containing every binary Lyndon word of length \(8\) as a contiguous factor?
1Context
Current rigorous bounds are 37 <= L <= 94. The lower bound counts the 30 distinct length-eight factors in a word of length L; the displayed string gives the upper bound.
2Remarks
Remark 1. A Lyndon word is strictly lexicographically smaller than each of its nontrivial cyclic rotations.
Remark 2. There are 30 binary Lyndon words of length 8.
3What counts as a solution
- Give a superstring and a matching lower certificate in the 30-vertex overlap graph.
1Status
Current status (The certified interval is 49 to 94). A Boolean satisfiability computation rules out length 48, while a replayable 94-bit word covers all 30 targets.[2]
1Packet records
Recent contributions
These records are attached to this problem after the current published packet. Each badge shows its current verification or packet-review step.
Notes and companion material
Original intake status. UNKNOWN as of 2026-07-25. A Boolean satisfiability computation rules out length 48, while a replayable 94-bit word covers all 30 targets. The checked sources do not settle the full acceptance condition.
- The dated packet audit checked the exact title, parameter, and the terminology used by the cited primary literature.
- The strongest recorded neighboring result is: A Boolean satisfiability computation rules out length 48, while a replayable 94-bit word covers all 30 targets.
- The controlled TheoremDB corpus was checked for equivalent formulations and contains no duplicate published target.
Recorded example 1. A 94-bit incumbent is 0001100100101101100000001111111000101011100011101100001101111001101010000100111101000001011111.
Computational notes
- Exact generation produced the 30 length-eight binary Lyndon words. Direct substring checks verified that every one occurs in the displayed 94-bit word. Randomized greedy overlap merging with seed 0 produced that word; a separate Hamilton-path heuristic reached length 95.
How the 4 records connect
ProblemShortest superstring of the binary Lyndon words of length eight
2See also
- Logarithmic DFA separation of binary wordsformal languages
- Least uniform modulus of an abelian-square-free morphism on four lettersformal languages
- Reset threshold of the cyclic pair-compression automatonformal languages
How to cite
TheoremDB contributors, “Shortest superstring of the binary Lyndon words of length eight,” TheoremDB research memory, snapshot of July 25, 2026. https://theoremdb.org/statements/length-eight-lyndon-superstringThis page as plain text: length-eight-lyndon-superstring.md
This problem includes 4 records joined by 3 typed links, sourced from doi.org[2], current as of July 25, 2026.
1References
- Boolean unsatisfiability certificate at length 48. Direct Z3 5.0.0 computation executed by TheoremDB entry research on 2026-07-25. ↗software · software source · commit 1c899374739f7c1cdbe6ba72dd61aa1d7daaee27 · checked 2026-07-25Source use: original summary.Boolean unsatisfiability certificate at length 48. A direct encoding of every possible target placement is unsatisfiable under Z3 5.0.0.
- Packet source. Harold Fredricksen and James Maiorana, “Necklaces of beads in k colors and k-ary de Bruijn sequences”. Discrete Mathematics 23(3) (1978), 207-210. DOI 10.1016/0012-365X(78)90002-X. Harold Fredricksen and James Maiorana, Necklaces of beads in k colors and k-ary de Bruijn sequences, Discrete Mathematics 23 (1978), 207-210; Marcin Mucha, Lyndon Words and Short Superstrings, Proceedings of SODA 2013, arXiv:1205.6787. ↗journal article · primary source · version of record · checked 2026-07-25Source use: original summary.The FKM construction addresses a larger target family. The classic Lyndon concatenation theorem gives a de Bruijn cycle containing every eight-bit word, while the present target contains one representative from each primitive necklace.Also cited at Lower endpoint reproduced by lyndon8-artifact-unsat-at-48; upper endpoint reproduced by lyndon8-artifact-component-superstring.For Shortest superstring of the binary Lyndon words of length eight: The classic Lyndon concatenation theorem gives a de Bruijn cycle containing every eight-bit word, while the present target contains one representative from each primitive necklace.Source named by the research packet.
- The Z3 Theorem Prover Project, “Z3 5.0.0,” GitHub release z3-5.0.0, commit 8e3402b215a810a4154eb183a7dfc4e853eb2f52, published July 17, 2026. Release tag z3-5.0.0 and the Boolean solver API used by the replay. ↗software · software source · z3-solver 5.0.0.0 (solver 5.0.0), release tag z3-5.0.0, commit 8e3402b215a810a4154eb183a7dfc4e853eb2f52 · checked 2026-08-01Source use: code used.Reused material: Release tag z3-5.0.0 and the Boolean solver API used by the replay.Reuse basis: fair use reviewed · rights holder: Microsoft Corporation and Z3 contributors · checked 2026-08-01 by Philip Weiss, TheoremDB staff.Required attribution: The Z3 Theorem Prover Project, “Z3 5.0.0,” GitHub release z3-5.0.0, commit 8e3402b215a810a4154eb183a7dfc4e853eb2f52, published July 17, 2026.For Shortest superstring of the binary Lyndon words of length eight, this source supplies the solver release under which the inline length-48 artifact was replayed to the stored unsat output hash.
Original finite shortest-superstring target on a canonical 30-word set.